I'm a happy APPJ owner for 6 months now. I suggest getting a 6P1->6AQ5 socket adapter which will greatly widen your output tube rolling options. Russian 6P1P-EVs aren't bad but I'm getting better results with 6005 Sylvanias, another benefit the amp runs much cooler with them due to the 6005/6AQ5's lower heater current and extra space between the tube and the enclosure due to the adapter. Had RCA 6AQ5s as well, they were nice but somehow became bright with use and slightly microphonic. There is a multitude of options for the driver tubes, I'm running GE 5654W now, but have some 1950s Philips 5654s on order, came across some reports on head-fi Mullard/Philips providing richer low-end. The amp gets plenty loud with my Klipsh RB-15 bookshelfs. I have an itch to try one of those Fostex kits from madisound for near-field, but low-end will probably suffer as compared to the Klipsches. Now, if I could also get rid of the hum...